The present invention relates to electronic control apparatus, and in particular to apparatus for controlling the locking and unlocking of vehicle doors in response to electronic signals.
The latter half of the twentieth century has been witness to a phenomenon known as the information revolution. While the information revolution is a historical development broader in scope than any one event or machine, no single device has come to represent the information revolution more than the digital electronic computer. The development of computer systems has surely been a revolution. Each year, computer systems grow faster, store more data, and provide more applications to their users. As the capabilities of computers have increased, the price of resources necessary to perform a given computing task has declined precipitously. This has made it possible to put computer capability in applications that were unthinkable not long ago.
One such application is the control and monitoring of motor vehicles. Most modern motor vehicles have at least one on-board microprocessor, which is in fact a small computer.
The microprocessor may be used, e.g., for controlling air/fuel mixtures, engine ignition timing, or other variables which affect engine performance. It may also be used for controlling systems not directly related to engine operation, such as an air conditioner. It may even be used for applications which are not strictly control systems at all, such as providing information to the driver about vehicle location, weather, diagnostics, and so forth.
Since a motor vehicle is a very complex machine, the possible applications for on-board vehicle computers are enormous. As computer capabilities improve and decline further in price, it is reasonable to apply on-board computer systems to a larger number of tasks. Such tasks need not be absolutely necessary for vehicle operation. Tasks which simply improve the ease and comfort of the users are appropriate for computer applications. It is expected that many such tasks are not performed today, and being merely conveniences, the need, such as it is, is not recognized. However, continued progress in the art means that today""s luxuries are tomorrow""s conveniences, and that eventually these may be seen as necessities. The electric starter motor was initially regarded as such a luxury, yet it would be hard to imagine an automobile today without one.
Many modern automobiles are equipped with electronically activated door latches. These may be activated by a portable remote control device transmitting a low-power radio signal, or may be activated by a switch which is an integral part of the vehicle, and is directly connected to the vehicle""s wiring. Such activation mechanisms may activate multiple doors simultaneously. Typically, a door latch may be locked or unlocked, and the door may be opened, by purely mechanical means (such as pulling on a handle within the vehicle to unlock and open the door). The electronic latching mechanism activates a solenoid, which forces motion in a mechanical part of the latch, thus providing an alternative means for locking or unlocking the latch.
The existence of alternate mechanical and electrical means has the potential to cause conflicts. If one person attempts to open a door latch by mechanical means, while another simultaneously attempts to unlock it electronically, the latch may fail to unlock. Because each person may not realize immediately what the other is doing, there may be multiple unsuccessful attempts to unlock the door, until one realizes what is going on and lets the other proceed. Furthermore, depending on the design of the latch, it is even possible for the latch to enter an intermediate state from which it can not be directly unlocked, but most fist be returned to the locked state (e.g., by activating a xe2x80x9clockxe2x80x9d switch), and then unlocked.
An unrecognized need exists for the application of on-board computer technology to prevent or reduce the occurrence of such annoying behavior.
A sensor detects a possible attempt to open a vehicle door latch by mechanical means, and temporarily disables an electronic unlocking signal until the mechanical activation means are absent.
Preferably, all functions are performed in the vehicle""s on-board microprocessor controller. An electronic signal to unlock a door is routed through the microprocessor, and will not activate the door lock without some positive action on the part of the microprocessor. Upon occurrence of an unlock event, such as receipt of an unlock signal or a predefined automatic unlock event, the controller checks the state of the door sensor(s). If the sensor(s) indicate that a person is or may be attempting to open the door mechanically, no unlock signal is transmitted immediately to the door latch. In this case, the controller may issue an audible beep to the user.
Preferably, the controller continues to check the state of the door sensor(s), and will activate the unlock mechanism after the sensor is clear. However, if the sensor is not clear within some timeout period, the controller will simply stop checking and will not activate the latch electronically. This is done to avoid confusing the user with an unlocking action some time after pressing the unlock switch. It would alternatively be possible to not use a time-out, i.e., if the sensor is not immediately clear, no signal is transmitted, or to use an xe2x80x9cinfinitexe2x80x9d timeout, in which case the controller unlocks the door whenever it is clear, no matter how long it takes.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which: